Optical communications are considered as potential replacements for electrical communications for the transmission of information and control signals from one point to another. One of the advantages of optical over conventional electrical communications is the broad band width capability which affords flexibility in the selection of a band width to be utilized in any given system. Cables used in optical communications systems are comprised of fiber lightguides which are small in physical size, light in weight and have a potentially low cost, but it is generally recognized that a prerequisite to the eventual acceptance of fiber lightguide cables is the development of reliable and simple fiber lightguide splicing arrangements.
Because of the small size of fiber lightguides, i.e. typically in the range of several micrometers to several hundreds of micrometers in diameter, it is generally considered preferable to be able to handle and splice them in groups or bundles, rather than on an individual basis. One kind of group is commonly referred to as a ribbon and includes two or more fiber lightguides which are held in contiguous, parallel relationship in a flat single layer or planar array. A plurality of ribbons are formed into a stack which is then jacketed, wrapped with strength members and enclosed with an outer jacket. The stacked ribbon structure, which is commonly referred to as a matrix in which the relative positions of the fiber lightguides are maintained throughout their length, greatly facilitates a splicing operation.
Although, it is desirable to be able to manufacture a ribbon in a single operation, problems have arisen in attempting to organize a relatively large number of the lightguides into a planar array without undue line tension and without the occurrence of crossovers.
Other concerns which are engaged in the production of fiber lightguide cables apparently have not addressed themselves to the foregoing problems of organizing a relatively large number of individual fiber lightguides. During ribbon manufacture, these concerns have advanced the fiber lightguides through individual tubes or guides which because of space limitations cannot be used to organize the relatively large number of fiber lightguides which are organized in accordance with the present invention.
Although concerns which make optical communications cables seemingly do not offer a solution to the problem of organizing a relatively large number of fiber lightguides, U.S. Pat. No. 3,130,453 teaches the organization of or change in width of a relatively large number of textile fibers into a small, tight or larger, looser bundle. It is also known to pass a band of fibers through a forming trumpet which rolls the band inwardly on itself from its outer edges to give it a cylindrical form, and to use rods located in vertical parallel planes to converge threads and form a ribbon with organizing forces which increase toward the center of the ribbon.
In order to organize fiber lightguides contiguously into a flat, single layer array, it is desirable that they be exposed to forces which are small enough to avoid damaging the lightguides, yet large enough to move them together. Nowhere in the known prior art are there shown methods or apparatus for organizing a plurality of fiber lightguides in a reproducible manner into a flat, single layer array in which the lightguides are in contiguous relationship with one another.